Each of the rooms is a different color, symbolizing the seven deadly sins. The ebony clock has a special place though. It is ticking down the time to their doom, because Prince Prospero has locked away himself and all of his wealthy friends in order to save them from the plague.

The “gigantic clock of ebony” stands on the western wall. It symbolizes death, and the clock is placed on the western wall because that is where the sun sets.

Its pendulum swung to and fro with a dull, heavy, monotonous clang; and when the minute-hand made the circuit of the face, and the hour was to be stricken, there came from the brazen lungs of the clock a sound…

The sound is important. It is “clear and loud and deep and exceedingly musical,” but it is so strange that the orchestra stops every time the clock strikes the hour. The clock stops time by marking time. Even though the revelers do not know it, the clock is ticking time away to their doom.